1. Field of the Invention
The present invention relates to an apparatus, system, method and program for processing information and, in particular, an apparatus, system, method and program for detecting a touch or the like on a real or virtual object using positional information of a detection target in space such as a human hand or finger to be detected by contactless type sensor means.
2. Description of the Related Art
An operation button or touchpanel may be typically used for a human operator to enter an operational input. The touchpanel is combined with a flat display such as a liquid-crystal display (LCD), and an operator presses a button icon displayed on a display screen to perform an input operation.
The input operation is performed based on a touch or a pressure applied on a flat surface of an operation button top or a touchpanel screen. An operation limited to touching or pressing serves as an input operation. The application of the input operation is limited to an area where touching on the flat surface is permitted.
Vibration or force caused by touch or pressure can degrade the performance of apparatuses, and blemish or damage the contact surface of the screen.
Japanese Unexamined Patent Application Publication No. 2008-117371 assigned to the same assignee of this invention discloses a proximity detection information display apparatus. In accordance with the disclosure, sensor means including a sensor panel having a plurality of line electrodes or dot electrodes arranged in two mutually perpendicular directions is used.
The sensor means detects a distance of a detection target to the surface of the sensor panel containing the plurality of electrodes, by detecting a capacitance responsive to the distance with respect to the plurality of electrodes. The detection target may be a human hand or finger and spaced apart from the surface of the sensor panel.
A capacitance between each of the plurality of electrodes on the sensor panel and the ground point varies depending on the position of the human hand or the human finger and the spatial distance of the human hand or the human finger to the panel surface. A threshold value is set in the human finger position and the spatial distance of the human finger to the panel surface, and a change in the capacitance responsive to the distance is detected in order to determine whether the finger gets closer than or farther apart than the threshold value.
Japanese Unexamined Patent Application Publication No. 2008-117371 discloses a technique that increases the detection sensitivity of capacitance by changing the spacing between the capacitance detecting electrodes depending on the distance between the detection target and the sensor panel.
The disclosed technique allows an operator to enter a switching input without touching the sensor panel. Since the sensor panel includes the plurality of line electrodes or dot electrodes in the mutually perpendicular directions, the disclosed technique allows the movement of the hand or finger in parallel with the plane of the panel surface to be detected. The input operation responsive to the movement of the hand or finger within space is performed.